The present invention concerns a wristwatch including a support attached to a wristband and a case containing a clockwork movement and display means, the case being mounted on the support so as to be able to slide and turn over to show respectively one or other of its faces in two operating positions, the watch including means for holding the case in its two operating positions, the support comprising two parallel inner surfaces each including a longitudinal groove closed at its ends, the case including, facing said inner surfaces, two parallel lateral walls each having a snug able to slide in the corresponding groove of the support, each of the grooves including at least one stop, disposed at a distance from its ends, the effect of said stop being to define a stop zone for the case, after a first sliding travel of the snug from one end of the groove, to let said case turn over, before said snug performs a second sliding travel to the other end of the groove.
A wristwatch of this type has been known for a long time. Additional Certificate No. 41 060 to French Patent No. 712 868 granted on Aug. 3, 1931 shows different variants. In a first variant, the watch case is free to pivot, to turn over on itself, at any place on the support. In another variant, this pivoting freedom is restricted. Indeed, the arrangement of the mechanism is such that the case can only pivot and turn over at the ends of the support, recesses being provided for this purpose.
However, these embodiments have a major drawback in common. The manufacturer of such watches can choose to favour ease of handling of the mechanism, in which case he will not use too hard a spring to hold the case in its operating positions, in order to make the latter easier to release. In such case, the mechanism will be made too sensitive to abrupt movements by the user""s wrist, said movements being able to cause the case to pivot inadvertently. In order to overcome this drawback, the manufacturer may choose to use springs of greater hardness, in which case it becomes difficult to handle the mechanism and the mechanical parts are exposed to premature wear.
The object of the present invention is to improve watches of this type so as to avoid the aforecited drawbacks.
The invention therefore provides a wristwatch of the type indicated hereinbefore, characterised in that it further includes means for preventing the case from pivoting outside said stop zone and thus said stop zone being a pivoting zone.
In a particular embodiment, said means for preventing the case pivoting outside said pivoting zone may be formed by at least one guide surface on the support, against which a surface of the case can abut by sliding.
One may also provide, in each groove, a recess located facing the stop, to allow the corresponding snug to get over the latter. One may, in this embodiment, use other means, such as the use of snugs of elongated cross-section, of greater length than the height of the groove, so that they can only pivot in the pivoting zone defined by the position of the stop and in which sufficient space is provided.
The case will thus pivot exclusively in the pivoting zone at a distance from the ends, removing any risk of inadvertent pivoting connected to an abrupt movement of the wrist.
In a preferred embodiment including said guide surface on the support, each groove may be formed of two successive sections, substantially parallel to the guide surface, and located at different distances from the latter, thus defining a high section and a low section, said sections being connected by a vertical break. In particular, the snugs of the case can be offset with respect to each other in height, said grooves being placed such that the high section of one is opposite the low section of the other and vice versa.